Page 11 - Clinical Connections - Summer 2023

Research News

THE EPIDEMIOLOGY OF MAMMARY TUMOURS IN ENGLISH COCKER
BOXER DOGS FEMALE CATS SPANIELS – HEALTH AND
TEMPERAMENT
RVC VetCompass has undertaken the An RVC VetCompass study can help
largest ever study on boxer dogs using veterinary surgeons identify cats at greater RVC VetCompass research has shown that
veterinary clinical records. The study drew risk of mammary tumours and better dental disease, ear infection, obesity and
on a random sample of 3,219 boxers advise on management and survival after aggression are among the most common
(0.96%) from an overall population of diagnosis. Mammary tumours in cats are problems diagnosed in English cocker
336,865 UK dogs of all breeds under first uncommon but can be highly aggressive spaniels.
opinion veterinary care during 2016. when they do occur. The English cocker spaniel has long
The results will help both owners and The study aimed to report the clinical been a popular family dog breed in the UK
vets provide breed-focused preventative signs and estimate the incidence and risk and is generally considered fairly healthy.
healthcare as well as help anyone thinking factors for mammary tumours in female However, there has been relatively little
of getting a boxer to know what to expect. cats attending UK primary care practices. information until now on the overall health
There has been concern about the impact The study included 259,869 cats under of the breed.
of their brachycephalic (flat-faced) status veterinary care in 2016. The RVC team examined the records
on health risks and that boxers with white Key findings included: of 10,313 English cocker spaniels from an
coats may have a higher risk of deafness • The average age at diagnosis for overall sample of 336,865 dogs of all breeds
from birth. However, there has been limited mammary tumours was 12.0 years under first opinion veterinary care. It was the
evidence on the overall health status of the • The proportion of cats diagnosed with largest study ever carried out on the health
breed, which the study sought to redress. a mammary tumour in 2016 was 0.1% of the breed based on veterinary clinical
The most common colours of the dogs • The most common clinical signs of records.
were brindle (23%) and dark red (23%) with mammary tumours in female cats The average adult bodyweight was 15.05
11% being white. Despite previous concerns, were ulceration in the mammary region kg, which makes this breed an often ideal
there was little evidence of comparatively (18%), weight loss (17%), hard mass size as a family pet. Males were generally
elevated health risks or shortened life spans (16%), loss of appetite (10%) and heavier than females (16.14 kg vs 13.80
of white boxers. However, low levels of discharge from the mammary region kg respectively). The average lifespan was
information on deafness in clinical records (7%) 11.44 years, which is close to the typical
and the possibility that some deaf dogs were • Purebred cats were 1.6 times more lifespan of 11.2 years previously reported
euthanised at an early age did not enable likely to be diagnosed with mammary across all dog breeds in the UK. Female
definitive conclusions on deafness. tumours than crossbred cats. English cocker spaniels lived longer
The average lifespan was 10.5 years • Older age was significantly associated than males (12.01 years vs 11.00 years
with the diagnosis. Cats aged 8-11
– similar to many other breeds of this Mammary tumours in female cats respectively).
body size. Although many of the common years were 2.5 and cats ages 11-15 Periodontal disease was diagnosed in
disorders of boxers were typical problems Mammary tumours in cats are uncommon but can be 20.97% of dogs each year, otitis externa
years were 5.1 times more likely to be
highly aggressive when they do happen. Survival time
from diagnosis has been previously reported at 8 to
of dogs overall, there were some specific 12 months after diagnosis. Previous research using (10.09%), obesity/overweight (9.88%), anal
diagnosed than cats aged 5 to 8 years
veterinary referral data suggested that breed, age and
neuter status were associated with the risk of cats
areas where health risks substantially higher • Average survival after mammary sac impaction (8.07%), diarrhoea (4.87%)
developing mammary tumours.
in boxers, such as eye ulcers, masses on This study aimed to report the clinical signs and estimate and aggression (4.01%). The frequency of
tumour diagnosis was 18.7 months
the incidence and risk factors for mammary tumours in
the wider population of female cats attending primary
the gums and cancer in general. care practices in the UK. The study included 259,869 each disorder was generally higher than the
female cats under veterinary care in 2016.
The most commonly recorded specific Proportion general dog population, possibly because
Proportion of cats with
of diagnoses
disorders of boxers included otitis externa mammary tumour diagnosed histopathology Average age at diagnosis a number of them are related to the longer
that included
in 2016
for mammary tumours
(7.15%, epulis (5.84%) corneal ulceration ears and lips and generally looser skin of
(5.00%), periodontal disease (4.63%), heart 0.1% 19.3% 12 years English cockers.
(270 cases
murmur (4.29%) and skin mass (4.29%). from 259,869 cats) (52/270) (interquartile range: Aggression was more common in males
8.5-14.0)
The most commonly reported overall than females, and in single-coloured
groups of disorders were skin disorders than multi-coloured dogs. Aggression
(17.74%), neoplasia (tumours/cancers) Clinical signs of mammary tumours risk varied widely between the four most
(14.20%) and ear disorders (10.41%). Cats generally presented with multiple clinical signs. common single-coloured coat colours.
The most common causes of death were The 5 most common clincal signs Discharge Golden-coloured dogs showed the highest
from the
neoplasia (12.43%), brain disorders (9.54%) Ulceration of mammary tumours mammary frequency of aggression (12.08%), followed
in the
in female cats were:
mammary region region
and mass lesions (8.38%). (18%) Loss (7%) by red (6.52%), black (6.29%), and liver
of
appetite
Weight Hard (10%) (4.33%).
loss mass
(17%) (16%)
Research paper: O’Neill et al. (2023)
‘Demography, common disorders and mortality of
Boxer dogs under primary veterinary care in the UK’, Risk factors for mammary tumour diagnosis Research paper: Engdahl et al.. (2023)
Canine Genetics and Medicine Research paper: Pickard Price et al. (2023) ‘Demography and disorders of English Cocker
‘Epidemiology and risk factors for mammary Spaniels under primary veterinary care in the UK’,
tumours in female cats’, Journal of Small Animal Canine Medicine and Genetics
11 to <15
5
years
Practice
4 (compared to cats
Relative risk of mammary tumour diagnosis TIMES INCREASED RISK 3 2 8 to <11 years to crossbred Summer 2023 11
Age
5 to <8 years)
15+
Breed
(compared
years
cats)
1 Purebred
65% of cases did not undergo
surgery. Of those that did receive
surgery, the most common types The average survival time after
were tumour/mass local removal mammary tumour diagnosis was
(23%), followed by unilateral 18.7 months.
mastectomy (11%) and bilateral
mastectomy (2%).
Conclusions
Survival after diagnosis The study can help
Older age and purebred was longer than previously veterinary surgeons
status were significantly reported and may reflect the identify cats at greater risk of
associated with mammary reality of primary-care cancer mammary tumour and advise
tumour diagnosis. compared to referral centre on survival after diagnosis.
and insurance based
studies.
CLICK TO READ THE FULL STUDY
Pickard Price, P. et al. (2023) “Epidemiology and Risk Factors for Mammary Tumours in female cats”
RVC VetCompass https://www.rvc.ac.uk/vetcompass carries out welfare research based on anonymised clinical information shared from over 30%
of UK veterinary practices. We are very grateful to the owners and veterinary professionals who contribute to VetCompass research.